A FPGA-based qpsk neural network demodulator and its control method

Abstract

The invention relates to a QPSK neural network demodulator based on an FPGA, and the demodulator comprises a clock and reset module, a reset signal, an AD sampling module, an input buffer module, a phase mutation detection module, a constellation rotation and data turnover module, and a synchronous output module. The clock and reset module is used for sending a clock signal and a reset signal; theAD sampling module is used for sampling the to-be-demodulated signal to obtain sampling data; the input buffer module is used for receiving and caching the sampling data and performing clock domain conversion on the sampling data; the phase mutation detection module is used for detecting relative phase change in the sampling data after clock domain conversion and outputting phase mutation information; the constellation rotation and data turnover module is used for receiving and processing the phase mutation information to form baseband data; and the synchronous output module is used for synchronously judging the baseband data and generating and outputting the demodulation data. The demodulator provided by the invention is low in parameter complexity and high in structural stability, the adaptability of the demodulator to a special environment can be improved through targeted training, one-dimensional convolution operation is carried out by applying the time delay network, the calculation complexity is reduced, and the use efficiency of hardware resources is improved.

Description

technical field [0001] The invention belongs to the technical field of digital communication, and in particular relates to an FPGA-based QPSK neural network demodulator and a control method thereof. Background technique [0002] The modulation and demodulation link is a crucial process in the digital communication system. The so-called modulation is the process of loading the baseband signal onto a higher frequency electromagnetic wave signal for the convenience of signal transmission, and demodulation is the reverse process of modulation. , is the process of moving the signal from a higher frequency to a lower frequency. Generally speaking, the input signal of the demodulator will introduce many non-ideal factors in the process of transmission and reception, including environmental noise, multipath effect, electromagnetic interference of receiving equipment, etc. The existence of these factors puts forward higher requirements on the performance of the demodulator. It can b...

AI Technical Summary

Problems solved by technology

In this method, there are a large number of configurable parameters, including filtering parameters, numerically controlled oscillator parameters, phase detection parameters, loop parameters, etc., and each parameter may affect the demodulation performance, which causes the demodulator The robustness of the system is poor, and it cannot be upgraded and improved for a special environment, such as frequency offset

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